"Tuned Light" Turns Opaque Materials Transparent

It’s been a long-standing prediction of physics that visible light can actually pass through such “opaque” scattering mediums, using transparent channels known as eigenchannels. That theory has now been experimentally verified, thanks to a pair of researchers at the optical physics department of the University of Twente, Netherlands.

The two, Ivo Vellekoop and Allard Mosk, exploit the fact that such “disorded” mediums are fixed in time, and thus the seemingly random scattering process can be partially reversed. The process requires tuning relative phases of portions of a light beam so that they constructively interfere with each other.